Wood chip flinger and method of densely packing wood chips

ABSTRACT

A handling device allows wood chips to be packed with a density greater than that achieved using conventional free-fall techniques by 20%-35% or more. The device includes a drum rotating about a generally horizontal axis that includes a plurality of outwardly extending blades that act to fling the wood chips so as to land with a substantially uniform orientation. The device may be attached to a movable boom and form a pile on the ground. The device may be used to pack a wood chip digestion chamber more densely. The device may also include a feed chute assembly that allows for adjustment of the ratio of the input stream that is delivered to the middle and side portions of the spinning drum. In some of these embodiments, this adjustment may be made while the device is operating, thereby allowing for on-the-fly adjustments by the operator.

[0001] This application is a continuation-in-part application of U.S.patent application Ser. No. 10/241,725, filed Sep. 11, 2002, stillpending, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to the field of wood chipprocessing, and more particularly to a machine and associated method fordense packing of wood chips for storage, transport, or processing.

[0003] One major factor in the cost of wood chips for paper making isthe cost of transporting the wood chips from the chip manufacturing siteto the paper mill. The wood chips are typically transported in railcars, but may also be transported in barges, trailers, or the like.Typically, the transportation costs are based primarily on the number ofcontainers used to ship a given load of wood chips. As more denselypacked containers means that fewer containers are required to ship agiven amount of wood chips, it follows that more densely packedcontainers will generally supply more useable wood chips to the papermill at a lower transportation cost.

[0004] Space considerations are also relevant in the storage andprocessing of wood chips. For instance, the storage of wood chips onsite, such as at a pulp mill, consumes space. As such, it isadvantageous to have the wood chips densely packed when “stacking” thewood chips for storage. Similarly, many methods of processing wood chipsinclude batch processing steps that take place in pressure vessels, orother containers, that have fixed volumes. If additional wood chipmaterials can be packed into the containers, the batch process canlikely be made more efficient.

[0005] Even with these considerations, many wood chip transporting,storing, and/or processing approaches rely on either conventionalfree-fall techniques or on techniques that result in packing densitiesof typically not more than 17% over free-fall techniques.

[0006] Accordingly, there remains a substantial need in the industry foralternate wood chip handling techniques that allow for higher packingdensities.

SUMMARY OF THE INVENTION

[0007] A wood chip handling device of the present invention allows woodchips to be packed with a density greater than that achieved usingconventional free-fall techniques. Preferably, the device packs the woodchips at a density that is at least 20% more than that achieved with theconventional free-fall techniques.

[0008] In one embodiment, the wood chip handling device includes amovable boom having a distal end. A redirecting device is supported bythe distal end of the movable boom, the redirecting device comprising adrum having a plurality of outwardly extending blades and a motor, themotor coupled to the drum so as to rotate the drum. A stream of incomingwood chips fed to the redirection device while the drum is rotatingabout a generally horizontal axis at a rate of 50 rpm or more isredirected to form an output stream of wood chips flung by the drum thatland with a preferential orientation. Preferably, while the boom movesin a first direction, the output stream is directed in the generallyopposite direction. The boom may rotate or move linearly. Preferably,the output stream forms a pile on the ground, optionally in the shape ofan arc or annular, having a packing density factor of at least 1.20.

[0009] In another embodiment, a method of processing wood chipscomprises feeding a stream of incoming wood chips to a drum disposed soas to rotate about a generally horizontal axis and spinning under powerat a rate of about 50 rpm or more, the drum including a plurality ofoutwardly extending blades; directing wood chips output from the druminto a wood chip digestion chamber; packing the wood chips in the woodchip digestion chamber to a density greater than a free-fall density;and digesting the wood chips in the digestion chamber for a period oftime. The wood chips in the wood chip digestion chamber may be packedwith a packing density factor of at least 1.20. The usual digestingchemicals may be added before, during, or after the wood chip loading,with the amounts thereof adjusted to accommodate the increased weightquantity of wood chips present in a batch. The digesting process maythen continue as in the conventional digesting technique.

[0010] Some embodiments of the present invention a feed chute assemblymay be used that allows for adjustment of the ratio of the input streamthat is delivered to the middle and side portions of the spinning drum.In some of these embodiments, this adjustment may be made while thedevice is operating, thereby allowing for “on-the-fly” adjustments bythe operator.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 shows one embodiment of the device of the present inventionemployed in a wood chip loading station for filling railcars.

[0012]FIG. 2 shows a perspective view of one embodiment of the device ofthe present invention.

[0013]FIG. 3A shows a side view of the embodiment of FIG. 2.

[0014]FIG. 3B shows a top view of the embodiment of FIG. 2, with theoptionally extended offset sections on the deadwall.

[0015]FIG. 4 shows a simplified top view of the drum and deadwall ofFIG. 2, with the optionally extended offset sections on the deadwall.

[0016]FIG. 5 shows a side view of the drum of FIG. 4 with the nearendcap removed.

[0017]FIG. 6 shows a front perspective view of the baseplate assembly ofthe embodiment of FIG. 2.

[0018] FIGS. 7A-7B show a side view and top view respectively of a woodchip inventory station using a moving boom with a flinger attachedthereto.

[0019]FIG. 8 shows a wood chip digestion station.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In order to provide a better understanding of the presentinvention, one embodiment of the wood chip handling device according tothe present invention is shown in FIG. 1 in the context of a wood chiploading station 10 for filling railcars 12. The wood chip handlingdevice, generally indicated at 20, is shown installed in a towerstructure 16 that extends above a rail line with a railcar 12 thereon.Wood chips 5 are fed to the handling device 20 in the tower 16 by anysuitable means, such as by conventional conveyor system 14 (only theoutput funnel of which is shown for clarity), or alternatively via apneumatic means into a cyclone, or by other like means known in the art.The handling device 20 takes the input stream of wood chips from theconveyor 14 and directs it into the railcar 12 so that the wood chips 5are relatively densely packed in the railcar 12. In most applications,the railcar 12 will be moved underneath the handling device 20 duringthe loading process so as to fill the entirety of the railcar's length,but the device 20 (with or without the tower 16) may alternatively bemoved while the railcar 12 is held stationary, if desired.

[0021] One embodiment of the handling device 20, sometimes referred toherein as the “flinger,” includes a frame 22, a motor 24, a feed chuteassembly 30, and a drum 80. The frame 22 supports the motor 24, feedchute assembly 30, and drum 80, and may take any suitable form known inthe art, such as welded assembly of angle iron. The motor 24 suppliesrotational power to the drum 80, typically via a pulley and beltarrangement (not shown). The motor 24 may be of any type known in theart, but is typically an electric motor of approximately fifteenhorsepower or more.

[0022] Disposed above the drum 80, and between the drum 80 and theconveyor system 14, is a feed chute assembly 30. Referring to FIG. 6,the feed chute assembly 30 includes a sloped baseplate assembly 40 andan optional deadwall 60 towards the output end 50 thereof. The baseplateassembly 40 of a preferred embodiment includes a baseplate 42 anddividers 46. The baseplate 42 is a sturdy, substantially rectangularplate with side flanges 44. The baseplate 42 is disposed in a tiltedorientation, so that the input end is higher than the output end 50.Referring to FIG. 6, the output end 50 preferably has a stepped profile,with a center section 52 flanked by respective side sections 54, andcorresponding transition sections 56. The center and side sections 52,54are preferably straight and parallel to one another, with the centersection 52 ending earlier than the side sections 54. The transitionsections 56 provide a transition between the center section 52 and theside sections 54. In a preferred embodiment, the overall appearance ofthe output end 50 of the baseplate 42 is that of a trapezoid cutout asshown in FIG. 6, but this is not required.

[0023] Two dividers 46 may be moveably attached to the baseplate 42 soas to be selectively positioned by pivoting about corresponding pivotpoints 47 (e.g., shouldered bolts extending through the baseplate 42).The location of the upper ends of the dividers 46 may be adjusted withrespect to the baseplate 42 using a suitable adjusting mechanism 48. Byway of non-limiting example, the adjusting mechanism 48 may take theform of a crank and threaded rod arrangement, with suitable pivotingconnections between the tops of the dividers 46 and the threaded rods.Of course, other means known in the art may be used to control theposition of the upper ends of the dividers 46. Whatever means isselected, it will be advantageous to position the controls thereof(e.g., the crank) so as to allow easy access thereto by a user duringoperation of the handling device 20. The purpose of the dividers 46 isto control the flow ratio of the wood chips flowing down the baseplateassembly 40 to the center 82 and side portions 84 of drum 80.

[0024] The deadwall, or directing wall, 60 is a generally vertical wallthat acts to focus the flow of the wood chips flowing down the baseplateassembly 40 generally vertically onto the drum 80. As shown in FIG. 2and FIG. 4, the deadwall 60 may include a center section 62, flankingside sections 64, and appropriate offset sections 66 therebetween. Thecenter and side sections 62,64 are preferably straight and parallel toone another, and preferably are disposed a height from the center ofdrum 80. The offset sections 66 are preferably generally perpendicularto the center and side sections 62,64 and are likewise disposed at thesame height from drum 80. Thus, the deadwall 60, when viewed from above,preferably has the shape shown in FIG. 4. Further, the deadwall 60should be located, and be of sufficient height, so that the wood chipsfrom the baseplate 42 impact in the vertical middle of the deadwall 60.It should be noted that the offset sections 66 may simply connect thecenter and side sections 62,64; or, alternatively, the offset sections66 may be longer such that they extend to a point well beyond theintersection with the center section 62, such as having approximatelytwice the length as shown in FIG. 4. This optional “extra” length forthe offset sections 66 is believed to aid in achieving the desiredside-to-side balance of wood chips being supplied to the drum 80.

[0025] The deadwall 60 is located forward of the output end 50 of thebaseplate assembly 40, so that a substantial gap is formed therebetweento allow passage of the wood chips without jamming as the wood chipschange flow direction. Further, while the deadwall 60 may be locatedprior to top dead center (behind the rotation axis 86 of the drum 80),the deadwall is advantageously located at a position that is beyond topdead center of the drum 80 (see FIGS. 3A and 3B). For the optimum gap tobe formed, the center section 62 of the deadwall 60 should be narrowerthan the center section 52 of baseplate 42 by about an inch, with thetransition sections 56 of the baseplate 42 extending laterallyapproximately another two inches. Of course, the gap size is at leastpartially governed by the spacing between the output end of thebaseplate assembly 40 and the location of the deadwall 60. The positionof the deadwall 60 relative to the baseplate 42 and/or drum 80 may bepermanently fixed; however, the position of the deadwall 60 may beadjustable (for instance, ±3 inches) in some embodiments of the presentinvention, such as by mounting the deadwall 60 using bolts, withmultiple bolt holes provided in the frame 22. It may be advantageous tovary the gap size, nominally eight inches, in proportion to the desiredoutput rate of the device 20.

[0026] While the space above the baseplate 42 of the feed chute assembly30 may be open, the feed chute assembly 30 may optionally include acover (not shown) spaced from the baseplate 42 to help contain anyerrant wood chips. The optional cover may extend above the top of thedeadwall 60, and be spaced therefrom, so as to provide an overflowroute, if desired.

[0027] The drum 80 is mounted for rotation about a generally horizontalaxis 86, and supported by the frame 22. The drum 80 may be mounted to anaxle 106, which may be a central shaft or a pair of stub shafts, whichis in turn supported by suitable bearings mounted to the frame 22. Asindicated above, the axle 106 should have a pulley, gear, or like meansfor accepting non-gravitational rotational power to turn the drum 80,such as from motor 24. The drum 80 includes a main body core 90 with aplurality of outwardly extending blades 100, and preferably a pair oflateral endcaps 94. The main body 90 of the drum 80 may have a circularcross-section, but preferably has a faceted cross-section, such as anoctagonal cross-section as shown in FIG. 5. The blades 100 are mountedto the core 90 so as to extend away from the surface thereof; forinstance, the blades 100 may extend generally perpendicular from thecorresponding facet 92 forming the perimeter of the drum 80. The blades100 should preferably extend from one lateral endcap 94 to the other.Each blade 100 may be a single straight piece, disposed parallel to theaxis of rotation 86 or at an angle thereto, for instance alternating±30°, or preferably ±10°. Alternatively, each blade 100 mayadvantageously include at least two sections 102 that angled withrespect to one another at angle α. For instance, as shown in FIG. 4,each blade 100 may have left and right portions 102 that meet in thecenter of the core 90 and are angled with respect to one another 1°-30°,preferably about 3°-10°. When this arrangement is viewed from above,each facet 92 of the drum's core 90 appears to have a chevron shapedblade 100 thereon (see FIG. 4). Each blade 100 preferably has anapproximately uniform height across its width, and the blades 100 arepreferably substantially identical, but neither aspect is strictlyrequired for all embodiments. A reinforcing gusset 104 may extendcircumferentially from one blade 100 to the next blade 100.

[0028] The handling device 20 may be used to load wood chips, andparticularly uniformly-sized paper making wood chips, into a suitablecontainer. The device 20 is mounted to the tower 16 of the loadingstation 10. A container, such as a railcar 12, is positioned below andforward of the handling device 20, and motor 24 is started to start thedrum 80 rotating. Before feeding wood chips to the device 20, the drum80 should be rotating at a rate of at least approximately 50 rpm, moreparticularly at least about 200 rpm, and more particularly atapproximately 350 rpm. When the drum 80 is spinning properly, wood chipsare supplied to the feed chute assembly 30 by the conveyor system 14.The wood chips slide down the baseplate 42, between the dividers 46, hitagainst the deadwall 60, and then fall as an input stream 200 to thedrum 80. The output end 50 of the baseplate 42, the deadwall 60, and thedividers 46 collectively control the relative proportions wood chipsbeing fed to the center 82 and side portions 84 of the drum 80. The woodchips fall to the drum 80 and are then flung forward by the blades 100of the spinning drum 80. The wood chips flung from the drum 80 arecaptured by the container 12. Due to the interaction of the feed chuteassembly 30 and the drum 80 spinning on a generally horizontal axis 86,the output pattern 210 of the wood chips leaving the drum 80 is suchthat the vast majority of the wood chips would (if unconstrained by thecontainer) land forward of the device 20 and within in an area thatangularly sweeps less than 180°. This output pattern 210 may beconceptually described as a truncated sector that sweeps angle β, whereβ is less than 180°. Indeed, β, is preferably less than 45°, and morepreferably less than about 20°. Further it should be noted that whilethe term “sector” has been used, the strict geometrical definition isnot meant, as the boundaries of the pattern 210 do not need to be arcshaped. Indeed, when β is very small, such as about 10°, the outputpattern may be described as substantially rectangular. Thus, definingthe output pattern 210 as a truncated sector means that the outputpattern where substantially all of the wood chips leaving the device 20would fall, if not deflected by intervening surfaces (such as walls ofthe container 12), forms any shape that does not fall outside a 180°angular sweep from the middle of the drum 80. Thus, the truncated sectoroutput pattern 210 is intended to include, without limitation, thepattern shown in FIGS. 3A & 3B, and similar substantially rectangularpatterns.

[0029] Even with a truncated sector output pattern 210, there may be anundesirable side-to-side distribution of the wood chips within theoutput pattern 210. For instance, the distribution of wood chips in theoutput pattern 210 to the middle subsector 210C, right side subsector210R, and left side subsector 210L may be uneven and/or otherwiseundesirable for some reason (e.g., output shifted left of center,leaving right side subsector 201R relatively unfilled). If the optionalvariably positioned dividers 46 are employed, then the ratio of outputflow to the various subsectors 210C,210R,210L may be adjusted by theoperator during operation (via adjusting mechanism 48) to reach thedesired ratios. Of course, adjustments can also be made to the drum 80rotational speed and to the wood chip supply rate from the conveyorsystem 14.

[0030] While the exact principles are not fully understood, the handlingdevice 20 of the present invention is able to pack wood chips within thecontainers 12 at density substantially higher than so-called free-fallloading. In free-fall loading, the wood chips from the conveyor system14 are directed to the container via a simple chute system. Examinationof free-fall loaded wood chips “packed” in a container show that theyland with widely varying orientations, sometime referred to as “jackstrawed” (like unstacked firewood), resulting in non-optimum density. Incontrast, the wood chips loaded via the present device 20 land with asubstantially consistent orientation, resulting in increased density.

[0031] The actual packed density achieved is expected to vary dependingon variations in size and moisture content of the wood chips. However, asimple ratio, referred to herein as the packing density factor, can beused to quantify the improvement provided by the present invention. Thepacking density factor is simply the ratio of the weight of wood chipsin a given volume when packed with the test device 20 divided by to theweight of the same volume of the same type wood chips (i.e., same sizeand moisture content), packed using the free-fall method. For instance,it is expected that a common 7100 ft³ railcar 12 loaded with wood chipsusing the free fall method will have approximately seventy-seven tons ofwood chips. It is expected that if the same type wood chips are loadedusing the device 20 of the present invention, the 7100 ft³ railcar 12would hold approximately one hundred tons of wood chips. Using thesevalues, the packing density factor for the present invention would be100/77=1.30. Clearly, substantial improvements in packing may beachieved using the present device 20, with resulting packing densityfactors in the range of 1.20 to 1.35 or higher. Just for reference,these type of packing density factors typically correspond to densitiesof 26.0 pounds/ft³ to 29.3 pounds/ft³ or more.

[0032] One example of the handling device 20 of the present inventionmay be made using a drum 80 with a diameter of approximately 18 inches,approximately 48 inches in width, and an octagonal cross-section ofapproximately 7 inch wide facets 92. The blades 100 may be approximately6 inches in height, with two sections of approximately 24-⅛ inchesmeeting at an angle α of approximately 8°, and spaced at intervals ofapproximately 7 inches. The gussets 104 may be approximately 3 inches inheight. The baseplate 42 of the feed chute assembly 30 may be at a 45°angle, with the 24-30 inch high deadwall 60 positioned such that thecenter section 62 is approximately 5 inches after top dead center andthe side sections 64 are approximately 10 inches after top dead center,for a gap of approximately 8 inches. The pivoting divider walls 46 maybe made adjustable, with a target distribution of 25%-50%-25% forfeeding to the left 84, center 82, and right 84 portions of the drum 80respectively. All portions of the device 20 contacting the wood chipsmay advantageously be made from ¼ inch abrasion resistant (AR) steel.The output pattern 210 of such a device should correspond to that shownin FIGS. 3A & 3B with β approximately equal to 8°-10°.

[0033] It should be noted that in order to minimize the escape of errantwood chips during loading, the frame 22 may advantageously includeadditional scatter shields at appropriate locations. The shieldlocations generally include on either side of the feed chute assembly30, and slightly downstream from the drum 80, but these locations mayvary depending on the details of a particular installation site.

[0034] The resulting truncated sector output pattern 210 when usingpreferred embodiments of the present invention is particularly suited tothe filling of rectangular containers, such as railcars 12. Prior artdevices which rely on a distribution device that spins about a generallyvertical axis tend to create round output patterns coveringsubstantially a full 360°, which are ill suited to filling rectangularcontainers. As the majority of wood chips shipped between domesticlocations are shipped by rail, using rectangular railcars 12, thepreferred embodiments of the present invention are more suited to theneeds of the industry.

[0035] The discussion above has shown the device 20 having an outputthat is forward and downward, which is believed to be advantageous formost applications. However, by moving the input stream of wood chipsrelative to the drum 80, from after top dead center to before top deadcenter, it is believed that the output may be changed to forward andupward, with the wood chips leaving such at device 20 having a slightly“lofted” trajectory. However, the resulting output pattern 210 shouldstill remain a truncated sector (e.g., generally rectangular), notcircular.

[0036] The discussion above has described a device 20 using a singlerotating drum 80. In most applications, this will be sufficient.However, the present invention is not limited thereto, and devices 20employing a plurality of drums 80 rotating about one or more generallyhorizontal axes 86 are intended to be encompassed by the presentinvention. The most likely arrangement for such a multiple drum 80arrangement would be to have the drums 80 located coaxially, in a mannereasily understood by one of ordinary skill in the art based on theteachings of the present application.

[0037] The densely packed output from the flinger 20 is useful indensely packing wood chips in a variety of containers, and even forstacking wood chips on the ground. For example, many wood pulp millsreceive wood chips generated at other locations and then store the woodchips as inventory for subsequently making wood pulp. It is common forthis “inventory” of wood chips to be stored in a pile on the ground 132,such as on rough cleared land or on a concrete pad. This pile istypically formed by the wood chips falling off the distal moving end 122of an inclined boom 120, with the wood chips routed thereto by aconveyor 114 that runs along the boom 120. The booms 120 may betrack-guided linear motion booms, or may be rotating type booms. In theformer case, the resulting pile of wood chips is typically an elongatedmound; in the later case, the resulting pile of wood chips has an arc orannular shape when viewed from above, as dictated by the rotating boom120. In both cases, the resulting pile is rather loosely packed, as itis formed by a free-fall process, with densities generally in the rangeof 1923 pounds/ft³. The flinger 20 of the present invention may be usedin such situations to allow more chips to be stored in the same space.FIGS. 7A-7B show a simplified representation of the flinger 20 suspendedfrom the distal end 122 of the boom 120, just below the output of theconveyor 114 on the boom 120. Thus, as the boom 120 moves in a givendirection 124, such as clockwise, the flinger 20 travels with the movingend 122 of the boom 120. The flinger 20 may advantageously be orientedsuch that its output 210 is directed generally opposite the direction ofmovement of the boom, as indicated by arrow 126. As the boom moves, theresulting pile 130 is formed behind the boom 120, but with significantlyhigher density compared to the conventional free-fall technique,typically on the order of 25-30 pounds/ft³. Thus, the pile 130 may besaid to have a packing density factor of 1.20 or more, and preferably apacking density factor of 1.3 or more.

[0038] The dense packing advantage of the flinger 20 may also be used toimprove the efficiency of various processes that use wood chips. Forinstance, the “digesting” process well known in the wood pulp industryuses wood chips loaded into a digestion chamber 140 with variouschemicals to generate wood pulp with the general consistency of mashedpotatoes. The digestion chamber 140 is operated in a batch mode, withthe wood chips and chemicals added, the digestion chamber (container)closed, and heat, high pressure steam, or the like, added for aspecified period of time, and then the digestion chamber is unloaded andthe process repeated on a new batch. The conventional technique forloading wood chips into the digestion chamber is to have the wood chipsfree-fall from a conveyor into an opening 142 in the top of thecontainer. Instead, according to the present invention, the flinger 20may be interposed between a conveyor system 14 and the opening 142. Theinput stream 200 of wood chips is fed to the rotating drum 80 of theflinger 20 so that the wood chips are redirected and flung into thedigestion chamber 140 with a preferential orientation so as to be packedtherein more densely. FIG. 8 shows a simplified representation of theflinger 20 disposed between the conveyor 14 and the digestion chamber140, with the output wood chips being flung downward through the opening142 of the digestion chamber so as to arrange themselves therein with apreferential orientation with respect to one another, thereby allowingfor tighter packing. The wood chips packed in the digestion chamber 140using the present technique may have a packing density factor of 1.20 ormore, and preferably a packing density factor of 1.3 or more. The usualdigesting chemicals may be added before, during, or after the wood chiploading, with the amounts thereof adjusted to accommodate the increasedweight quantity of wood chips present in a batch. The process may thencontinue as in the conventional digesting technique. By using theflinger 20 to aid in densely packing the wood chips in the digestionchamber 140, more wood chips may be processed by a given piece ofequipment in a given time period, resulting in a more cost effectiveprocess.

[0039] The increase in packing density readily achieved by the presentinvention has clear benefits to the industry. In the simplest terms,more wood chips can be packed into a smaller space, thereby loweringtransportation, storage, and processing costs. Further, given thesubstantial increase in packing density achieved, the cost savings canbe considerable.

[0040] While the invention has been illustrated and described in detailin the drawings and foregoing description, the same is to be consideredas illustrative and not restrictive in character, it being understoodthat only some embodiments have been shown and described and that allchanges and modifications that come within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. A method of handling wood chips, comprising:supporting a redirecting device with a distal end of a movable boom,said redirecting device comprising a drum having a plurality ofoutwardly extending blades; rotating said drum under power about agenerally horizontal axis at a rate of 50 rpm or more; feeding a streamof incoming wood chips to said redirection device and moving said boomin a first direction while rotating said drum; forming an output streamof wood chips flung by said drum, said output stream forming a pile onthe ground having a packing density factor of at least 1.20.
 2. Themethod of claim 1 wherein said feeding said stream of incoming woodchips to said redirection device comprises moving said wood chips upwardtowards said distal end of said boom.
 3. The method of claim 1 whereinsaid forming said pile on the ground comprises forming a non-linearelongate pile on the ground.
 4. The method of claim 1 wherein formingsaid output stream of wood chips comprises forming said output stream ina direction generally opposite said first direction.
 5. The method ofclaim 1 wherein moving said boom comprises rotating said boom in saidfirst direction, and wherein forming said output stream of wood chipscomprises forming said output stream in a direction generally oppositesaid first direction.
 6. An assembly for handling wood chips,comprising: a movable boom having a distal end; a redirecting devicesupported by said distal end of said movable boom, said redirectingdevice comprising a drum having a plurality of outwardly extendingblades and a motor, said motor coupled to said drum so as to rotate saiddrum; wherein a stream of incoming wood chips fed to said redirectiondevice while said drum is rotating about a generally horizontal axis ata rate of 50 rpm or more is redirected to form an output stream of woodchips flung by said drum that land with a preferential orientation. 7.The assembly of claim 6 wherein said boom moves in a first direction,and wherein said output stream is directed in a direction generallyopposite said first direction.
 8. The assembly of claim 7 wherein saidboom rotates in said first direction.
 9. The assembly of claim 6 whereinsaid output stream forms a pile on the ground having a packing densityfactor of at least 1.20.
 10. The assembly of claim 9 wherein said outputstream forms a pile on the ground having a packing density factor of atleast 1.3.
 11. A method of processing wood chips, comprising: feeding astream of incoming wood chips to a drum disposed so as to rotate about agenerally horizontal axis and spinning under power at a rate of about 50rpm or more, said drum including a plurality of outwardly extendingblades; directing wood chips output from said drum into a wood chipdigestion chamber; packing said wood chips in said wood chip digestionchamber to a density greater than a free-fall density; and digestingsaid wood chips in said digestion chamber for a period of time.
 12. Themethod of claim 11 wherein said packing said wood chips in said woodchip digestion chamber comprises packing said wood chips in said woodchip digestion chamber with a packing density factor of at least 1.20.13. The method of claim 11 further comprising adding chemicals to saidchamber prior to said digesting.